1. Field of the Invention
The present invention relates to a communication system, a base station, and an information providing method for providing information to a terminal device.
2. Description of the Related Art
Conventionally, systems to be utilized by a user of a terminal device at a time of passing through a road include a system for checking a current location of the terminal device and a system for providing a regional information such as that of restaurants, amusement spots, road maps, etc., according to the current location of the terminal device. In these systems, the location of the terminal device is detected by a method using the GPS (Global Positioning System), a method using the cell ID assigned to each base station provided in a service providing area of the so called cellular type portable telephone service, etc.
In the method using the GPS, a GPS receiver is provided on the terminal device, and the location is detected by receiving GPS signals transmitted from a plurality of GPS satellites. Also, in the method using the cell ID, the location is detected from the cell ID of the base station of a cell in which the terminal device is located by utilizing the cell IDs of the base stations that are necessary for the purpose of the cellular type portable telephone service.
On the other hand, when the user of the terminal device passes through a road, there is a need to obey the traffic signals for regulating traffic of the road. A state of the traffic regulation to be realized by the traffic signal is normally notified to the user by the color of a signaling light or the sound from a loudspeaker provided on the traffic signal.
However, in the method using the GPS described above, there is a need to provide the GPS receiver on the terminal device, and the power consumption of the GPS receiver is large so that there has been a problem that the power consumption of the terminal device increases. Also, in the method using the cell ID, there is no need to provide a special receiver, the location is detectable only in the cell ID unit so that there has been a problem that a precision of the location detection is low. For example, in the case of the PHS (Personal Handyphone System), there has been an error of approximately 100 m. In addition, because there is an error in the detected location of the terminal device, there has also been a problem that, even if the regional information according to the detected location is provided, the provided regional information will not match with the actual location of the terminal device.
Also, in the method for notifying the state of the traffic regulation by the traffic signal using the color of the signaling light or the sound from the loudspeaker provided on the traffic signal, there are cases where it is difficult to comprehend a message of the signal as in the case of a visually or aurally handicapped person or the case where it is unclear as to which sound is indicating which direction is traversable.
It is therefore an object of the present invention to provide a communication system capable of detecting the accurate location of the terminal device while suppressing the power consumption of the terminal device.
It is another object of the present invention to provide a communication system and an information providing method capable of enabling an easy comprehension of the state of the traffic regulation by the traffic signal.
According to one aspect of the present invention there is provided a communication system, comprising: a location information providing unit configured to provide a location information indicating a location of each road related facility arranged along a road; and a communication unit installed on each road related facility, configured to transmit the location information of each road related facility to a terminal device of a user on the road by using weak radio signals, such that the terminal device that can receive the weak radio signals can detect a location of the terminal device according to the location information.
According to another aspect of the present invention there is provided a communication system, comprising: a police server configured to manage police information database; and a communication unit installed on each road related facility arranged along a road, configured to receive a police information transmitted from a terminal device of a user on the road by using the weak radio signals, and transmit the police information to the police server.
According to another aspect of the present invention there is provided a communication system, comprising: a control unit configured to control a traffic signal on a road to carry out a traffic regulation; and a communication unit installed on the traffic signal, configured to transmit a traffic regulation information regarding the traffic regulation carried out by the traffic signal to a terminal device of a user on the road in response to a request from the terminal device.
According to another aspect of the present invention there is provided a communication method, comprising: providing a location information indicating a location of each road related facility arranged along a road; and transmitting the location information of each road related facility to a terminal device of a user on the road by using weak radio signals from a communication device installed on each road related facility, such that the terminal device that can receive the weak radio signals can detect a location of the terminal device according to the location information.
According to another aspect of the present invention there is provided a communication method, comprising: managing police information database at a police server; and receiving a police information transmitted from a terminal device of a user on a road by using the weak radio signals at a communication device installed on each road related facility arranged along the road, and transmitting the police information to the police server.
According to another aspect of the present invention there is provided a communication method, comprising: controlling a traffic signal on a road to carry out a traffic regulation; and transmitting a traffic regulation information regarding the traffic regulation carried out by the traffic signal from a communication device installed on each road related facility arranged along a road to a terminal device of a user on the road in response to a request from the terminal device.
Other features and advantages of the present invention will become apparent from the following description taken in conjunction with the accompanying drawings.